Physics Commons^™

Theoretical Investigation Of Interactions And Relaxation In Biological Macromolecules, Koki Yokoi

Theses and Dissertations

One of the major challenges posed to our quantitative understanding of structure, dynamics, and function of biological macromolecules has been the high level of complexity of biological structures. In the present work, we studied interactions between G protein-coupled receptors (GPCRs), and also introduced a theoretical model of relaxation in complex systems, in order to help understand interactions and relaxation in biological macromolecules.

GPCRs are the largest and most diverse family of membrane receptors that play key roles in mediating signal transduction between outside and inside of a cell. Oligomerization of GPCRs and its possible role in function and signaling currently …

Oligomerization Of The Sterile-2 G-Protein Coupled Receptor In Yeast Cells In The Presence And Absence Of Alpha-Factor Pheromone Using Fluorescence Spectroscopy And Forster Resonance Energy Transfer Analysis, Joel David Paprocki

Theses and Dissertations

G-protein-coupled receptors (GPCRs) are the largest family of receptors that respond to a wide variety of extracellular stimuli, including molecular ligands such as odorants, neurotransmitters, and hormones, as well as physical agents sigh as light and pressure. The stimulation event results in initiating conformational changes in the structure of the receptor, which further results in the release of the heterotrimeric G-protein; the latter has a variety of functions within signaling pathways in cellular biology. The GPCR explored in this investigation is the Sterile 2 α-factor receptor (Ste2), whose natural function is that of a yeast mating pheromone receptor. Its natural …

Two-Photon Microscopy For Biomedical Studies, Yassel Acosta

Open Access Theses & Dissertations

Fluorescence optical microscopy is one of the most important tools to investigate biological samples and to observe structures in living cells. Based on the principle of the simultaneous absorption of two-photons and subsequent emission of fluorescent light we have developed a Two-Photon Laser Scanning Fluorescence Microscope that allow us to perform optical sectioning and three-dimensional reconstructions of structures in biological samples such as dopaminergic clusters of neurons and tracheal branches in Drosophila brain. The spatial confinement of the excitation light to the focal plane combined with the temporal compression of photons into short packets during femtosecond pulses make our system …

Investigation Of The Quaternary Structure Of An Abc Transporter In Living Cells Using Spectrally Resolved Resonance Energy Transfer, Deo R. Singh

Theses and Dissertations

Förster resonance energy transfer (FRET) has become an important tool to study proteins inside living cells. It has been used to explore membrane protein folding and dynamics, determine stoichiometry and geometry of protein complexes, and measure the distance between two molecules. In this dissertation, we use a method based on FRET and optical micro-spectroscopy (OptiMiS) technology, developed in our lab, to probe the structure of dynamic (as opposed to static) protein complexes in living cells. We use this method to determine the association stoichiometry and quaternary structure of an ABC transporter in living cells. Specifically, the transporter we investigate originates …